During the high summer months, central Sweden is home to a fascinating mix of Scandinavian and Eastern European butterfly species. Several of these are found here at the southernmost limits of their ranges and in this part of Scandinavia, where north meets south, there might even be a few new discoveries to make, for only recently have populations of Large Blue, Chequered Blue and Duke of Burgundy been discovered. During this holiday we will be based in Svartådalen (the Black River Valley), a peaceful patchwork of wetlands, mixed woodlands and flowerfilled watermeadows that are home to a wonderful diversity of butterflies and dragonflies. Amongst the well-established species, highlights should include such charismatic butterflies as Clouded Apollo, Poplar Admiral and Scarce Copper. We also hope to see an abundance of blues — up to 11 species being possible! As this is also such a fantastic area for birds, we will be sure to take time to enjoy morning and late afternoon birding excursions around Lake Fläcksjön in search of such species as Black Tern, Spotted Crake, White-tailed Eagle, Thrush Nightingale and Common Rosefinch.
We begin our holiday with a direct flight to Västerås Airport, and then drive for one hour north to Svartådalen in the county of Västmanland. On our first full day we will head a little way to the south of Svartådalen, in search of the beautiful Poplar Admiral. At this time of year these butterflies are likely to be newly emerged and in pristine condition, and we hope to watch them descending from the canopy to take salts from wayside puddles. Common Swallowtail, Purple-edged Copper, Amanda’s Blue and possibly Northern Wall Brown can also be seen here. Later in the day we will visit a forest lake where Black-throated Divers are known to breed and around which we can look for Scarce Fritillary, Cranberry Blue, Northern Chequered Skipper and dragonflies such as Common Goldenring and Common Clubtail.
On another day we will head further south, visiting two highly productive butterfly sites, both on islands in the huge, sprawling Lake Mälaren. Here, the iconic Large Blue can be found on the slopes of an Iron Age burial mound, attracted by the patches of Wild Thyme that grow there. Green-underside Blue and Queen of Spain Fritillary can also be found on the adjacent grazed hillsides.
The Baltic coast and Fjarilsvagen Grinduga will be our focus on another day, where we will pay a visit to a site Swedish lepidopterists call the ‘Butterfly Road’ — an unassuming gravel track through a seemingly ordinary patch of pine forest. Here, not only do an interesting variety of orchids grow on the rich chalk soils but, as its name suggests, this is a great spot for butterflies such as Black-veined White, Silvery Argus and Large Grizzled Skipper. On our return journey to Svartådalen we will stop to look for another exciting species, the Clouded Apollo, but we will also be on the look out for a variety of dayflying moths including Broad-bordered and Narrow-bordered Bee Hawk-moths.
Sweden’s moths are not well known, and so on one or two nights we will run a moth trap near to our guesthouse. If time and weather permit, we will also try both a coniferous forest/bog site and a then a deciduous forest site to increase our species count. Northern Oak Eggar, several hawk-moths including Pine Hawkmoth, and the colourful ‘Peat-bog Carpet’ (Arichanna melanaria) are all possible.
On our final full day we will head north to an area where vast pine forests, lakes and mires dominate the landscape. This is the home of the rare Baltic Grayling, although, since this species has only one generation every couple of years, it’s not a butterfly we will see on every tour! Other species to look out for include Bog and Cranberry Fritillaries, Moorland Clouded Yellow, Northern Grizzled Skipper and, if fortunate, perhaps the striking Assmann’s Fritillary, Sweden’s rarest butterfly! Birds of these northern taiga forests include Capercaillie, Black Grouse, Crested Tit and Pied Flycatcher.
There will also be the opportunity to enjoy Sweden’s diverse dragonfly fauna throughout the tour. Ruby and Small Whiteface are abundant, though we will need a bit of luck to spot a Bog Hawker or Small Pincertail among the commoner species. To see one of the smallest and most localised damselflies in Europe, however, the Sedgling (Nehelennia speciosa), we have only to journey a few minutes from our hotel!
We should have time on our final morning to further explore the meadows, mires and forests around Svartådalen before driving the short distance back to Västerås Airport in time to catch our return journey home.